title: Transmembrane potential of red blood cells under low ionic strength conditions.
abstract: OBJECTIVE
  In a variety of investigations described in the literature it was not clear to what extent the transmembrane potential red blood cells (RBCs) was changed after the cells have been transferred into low ionic strength (LIS) solutions. Another open question was to find out how fast the transmembrane potential of RBCs in LIS solution will change and which final new equilibrium value will be reached.
  
  
  METHODS
  The transmembrane potential of human and bovine RBCs was investigated using the potential-sensitive fluorescent dye DIBAC4(3) (bis(1,3-dibutylbarbituric acid) trimethine oxonol) as well as the CCCP (carbonylcyanide-m-chlorophenylhydrazone) method.
  
  
  RESULTS
  Under physiological conditions the transmembrane potential was about -10 mV in agreement with literature data. However, when the RBCs were transferred into an isosmotic low ionic strength medium containing sucrose the transmembrane potential increased to +73 mV and +81 mV for human and bovine RBCs, respectively. In case of human RBCs it continuously decreased reaching finally an equilibrium state of -10 mV again after 30 - 60 min. For bovine RBCs the transmembrane potential declined more slowly reaching a value of +72 mV after 30 min.
  
  
  CONCLUSIONS
  Investigations of parameters of RBCs depending on transmembrane potential cannot be performed with human RBCs in LIS media.
authors.affiliation: Laboratory of Biophysics, Faculty of Natural and Technical Sciences III, Saarland University, Building A2 4, Saarbruecken, Germany.
authors.forename: Daniel
authors.initials: D
authors.lastname: Moersdorf
authors.forename: Stephane
authors.initials: S
authors.lastname: Egee
authors.forename: Claudia
authors.initials: C
authors.lastname: Hahn
authors.forename: Benjamin
authors.initials: B
authors.lastname: Hanf
authors.forename: Clive
authors.initials: C
authors.lastname: Ellory
authors.forename: Serge
authors.initials: S
authors.lastname: Thomas
authors.forename: Ingolf
authors.initials: I
authors.lastname: Bernhardt
mesh_terms: D000818:Animals; D002258:Carbonyl Cyanide m-Chlorophenyl Hydrazone / Q000737:chemistry; D002417:Cattle; D004912:Erythrocytes / Q000502:physiology*; D005434:Flow Cytometry; D005456:Fluorescent Dyes / Q000737:chemistry; D006801:Humans; D008564:Membrane Potentials; D009994:Osmolar Concentration
chemical_list: D005456:Fluorescent Dyes; D002258:Carbonyl Cyanide m-Chlorophenyl Hydrazone